[PATCH] mm: make __put_page internal

Remove __put_page from outside the core mm/.  It is dangerous because it does
not handle compound pages nicely, and misses 1->0 transitions.  If a user
later appears that really needs the extra speed we can reevaluate.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/mm.h

@@ -308,7 +308,6 @@ static inline int get_page_unless_zero(struct page *page)
 }
 
 #define set_page_count(p,v) 	atomic_set(&(p)->_count, (v))
-#define __put_page(p)		atomic_dec(&(p)->_count)
 
 extern void FASTCALL(__page_cache_release(struct page *));
 

mm/filemap.c

@@ -30,6 +30,8 @@
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include "filemap.h"
+#include "internal.h"
+
 /*
  * FIXME: remove all knowledge of the buffer layer from the core VM
  */

mm/internal.h

@@ -8,6 +8,10 @@
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */
+#ifndef __MM_INTERNAL_H
+#define __MM_INTERNAL_H
+
+#include <linux/mm.h>
 
 static inline void set_page_refs(struct page *page, int order)
 {
@@ -26,5 +30,12 @@ static inline void set_page_refs(struct page *page, int order)
 #endif /* CONFIG_MMU */
 }
 
+static inline void __put_page(struct page *page)
+{
+	atomic_dec(&page->_count);
+}
+
 extern void fastcall __init __free_pages_bootmem(struct page *page,
 						unsigned int order);
+
+#endif

mm/vmscan.c

@@ -39,6 +39,8 @@
 
 #include <linux/swapops.h>
 
+#include "internal.h"
+
 /* possible outcome of pageout() */
 typedef enum {
 	/* failed to write page out, page is locked */